


destiny’s mate

by seohin



Category: Supernatural
Genre: Alpha Sam Winchester, Alpha/Beta/Omega Dynamics, Complete, Culture Shock, Episode: s05ep04 The End, Episode: s15ep13 Destiny’s Child, Established Castiel/Dean Winchester, F/F, F/M, Fuck Or Die, Gen, M/M, Omega Dean Winchester, POV Sam Winchester, heat - Freeform
Language: English
Status: Completed
Published: 2020-08-09
Updated: 2020-08-09
Packaged: 2021-03-06 01:27:03
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,174
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25795096
Author URL: https://archiveofourown.org/users/seohin/pseuds/seohin
Summary: In the kitchen, he pauses before rifling through the cabinets, finding the honey and eventually putting a pot of water to boil on the stove. As much as Dean hated the stuff, he’d once confided in Sam that it was pretty good when he was stuck without Cas on heats, and so Sam taught himself to brew tea, just in case.Looks like it was finally going to be used after all.-Or, the one where instead of two rich brats breaking the wall between worlds, it’s two ex-hunters who’re waiting for a third.
Relationships: Castiel/Dean Winchester, Dean Winchester & Sam Winchester
Comments: 13
Kudos: 58
Collections: The AO3 SPN Kink Meme





	destiny’s mate

**Author's Note:**

  * In response to a prompt by Anonymous in the [theao3spnkinkmeme](https://archiveofourown.org/collections/theao3spnkinkmeme) collection. 



> Unbeta’d
> 
> this took WAY too long to write. im not really into a/b/o in general so the info might not be fanonly accepted but the plot wouldn’t leave me and then i wrote too much to give up on it so here it is
> 
> Also quick note: other-__ is the dean sam cas we’ve seen, regular names = the alternate universe dean sam cas, bc this fic is written thro au!sam’s POV ; when it says shit in italics it doesn’t mean dean + sam have telepathy it means they know each other well enough to know what they’re thinking just by body language
> 
> (If you’d like to see the warnings check the end notes, but warning for spoilers)
> 
> (Also the banner is from the wonderful mods at the Ao3 SPN Kink Meme, for which this was written — if y’all wanna see more work from the community just check out the collection this is posted in!! The fics and mods are amazing :))
> 
>  **Prompt:** Instead of having the HunterCorp counterparts come through, Alpha Sam and Omega Dean find themselves in our world instead. [redacted]

_And if wishes came true / It would’ve been you / [...] / But it would’ve been fun / If you would’ve been the one_

_\- folklore, ‘the 1’ (Taylor Swift)_

Sam can’t believe they made it. He knows the absence of Cas is going to hit them pretty soon — Dean’s already fidgeting, pulling his collar over his mating gland — but for now, it’s enough.

“What the _fuck_?” Other-Dean says in what was probably supposed to be a whisper on their way to the kitchen. Sam just bites back a grin as he watches Dean close his eyes and shudder, because if not he thinks he’s going to burst into his ugly-cry if he actually processes what they pulled off.

What he does try to focus on is the way that Dean’s the only one who even _has_ a scent (leather, oil, metal, and pie, the same way it’s always been, though after he officially mated there’s something distinctly sulfur-ish in there that only serves to make him more homesick), because the way Other-Dean and Other-Him smell almost _scent-less_ is way too strange to be normal, and nothing works better than a good case to get his mind off of everything. Even suppressants smell distinctly tangy or minty, and the ones that advertise scent-less-ness just smell like lies. 

Other-Him pushes a beer into his hand with a thin smile that only has Sam cringing because if that’s how he looks when he’s uncomfortable how in the hell did he and Dean pull off their Fed routine for that long. There’s an uncomfortable silence during which both of them are probably trying to unravel the mystery — _Beta doesn’t make sense, don’t have scent-blockers_ , Dean tells Sam in a shift of his shoulders. _Can’t be non-presenters, they seem to be able to smell_ , Sam responds in a flick of his eyes, and then both of them look at each other with frustration while Other-Them pause and look back with furrowed eyebrows.

Other-Him finally just clears his throat. “So, uh, back home… you’re— you’re hunters?”

Dean and Sam shrug, and from the way Dean’s scent is becoming tinged with too much _Cas_ , Sam decides to answer. “We were, up until a few years ago. After Dean, uh, mated, and with Heaven and Hell on our ass, we figured it was best if we laid low, became ‘civilians’.”

They both chuckle lowly at that because they never _were_ able to really settle down, not with what they know, not with Dean mated to a fucking demon, but the other option was Cas getting sent back to Hell for a little reconditioning and him and Dean both dead, so it was a pretty okay deal, all things considered.

In front of them, Other-Dean and Other-Sam freeze, and then they carefully look at each other and it’s weird as hell, seeing them communicate in glances and touches the way he and Dean do, but not being able to understand it because they _are_ different, after all.

Finally, Other-Dean carefully leans forward, fingers laced together around his bottle in a way that’s so similar and yet so _different_ from the Dean Sam knows. “What do you mean, ‘mated’?” He even uses the finger quotes, and Sam just blinks, turning to glance at Dean, whose scent is still tinged with sadness but now confusion. They only look at each other for a moment but that’s all they need, and suddenly the sort of amiable mood in the room is shattered, the four of them looking at the others with suspicion even though they _are_ the others.

The Winchester way is to trust no one, though, so Sam supposes he understands. He doesn’t even trust himself. Quite literally.

“Mated,” Dean says carefully, and Sam takes care to keep his face passive as he notices Other-Him spotting the tell-tale signs of grief all over Dean’s face. “Ya’know, together? Don’t you guys have mating glands or whatever?”

Other-Him raises an eyebrow and shares another, loaded look with Other-Dean, and then just shakes his head. “No, we… don’t. What’s a ‘mating gland’?”

 _At least we’ve found the difference in the worlds_ , Sam sighs, and Dean glances at him, shrugging his agreement as Sam begins speaking. “A mating gland is a… it’s like… it’s a way to symbolize a true mating, ya’know? Some people use rings if they’ve already been pierced, but it’s how you know that they’re serious about each other, even if they do have a scent bond.”

“Okay, I’m lost,” Other-Dean says, and then he narrows his eyes at Dean’s visible sorrow, gesturing with his beer bottle. “And what the hell’s going on the—?” 

Other-Him puts a hand on Other-Dean’s arm, and Sam feels a strange sort of surprise when he and the Other-Him roll their eyes at the same time at Other-Dean’s lack of tact, even if Other-Him’s missing the anger that Sam has.

Other-Dean sighs and then just gestures for Other-Him to continue. “What he _means_ to say,” Other-Him stresses, “Is that we have no clue half of what you guys are saying.”

Sam sighs as Dean pulls himself out of his funk, shoving the gaping absence of his mate aside to deal with the here and now in a way he was all-too-skilled in doing. Slipping into his ‘interrogation’ mode that almost projected him like an Alpha until you got his scent, he got his game face on.

“What’re your guys’s genders?” Dean hedges, and only his body language (taught at the shoulders, _missing Cas_ , hand twitching slightly, _still angry at himself for not killing Eileen’s killer in time to save her five weeks ago_ ) lets Sam know that something’s wrong.

“Dudes. We’re guys. _Obviously_.” Other-Dean raises an eyebrow and gives a ‘explain’ gesture that makes Sam’s blood boil, but _technically_ they’re brothers so he just pastes on his bitchface.

“That… literally makes no sense. What’s your _gender_?”

There’s a very pregnant pause, and then Other-Them carefully, in unison, say, “We’re ‘males’,” finger quotes and all.

Beat.

“What’s a male?”

Other-Them turn to look at Sam with wide eyes, and then Other-Him asks, hesitantly, “...what’re _your_ guys' genders?”

“He’s an Alpha, I’m an Omega.” Dean kicks his feet up on the table, but the nonchalance is just a show, and all of them know it. Other-Dean’s mouth opens and closes, vaguely fish-like, almost, and Other-Him looks practically catatonic.

“...I’m sorry?” Other-Him finally says, voice squeaky. Before Sam can respond, Other-Him continues, “But you guys called each other— you guys called each other ‘bros’ when you first arrived, and— and, you use _male_ pronouns.”

 _I’m going to take pity on him_ , Dean says with a swig of his beer, and he shoots Sam a cheesy wink that lets him pretend, for a second, that they’re back home and just doing another case for old time’s sake. “Yeah, we’re brothers, but that’s from our child designations. When we were both boys? And, by the way, what the hell’s a ‘male’? Is that what you guys call trans-presenters here?”

“That means we have _dicks_ wha—”

“—you know what, this is going nowhere,” Other-Him interjects, and he stands up, continuing. “Dean and I need to go for something, but I guess this is… perfect, really. Just stay behind if Chuck decides to pop in and see what the Winchesters are up to in this episode. You guys cool with that?”

Sam and Dean nod the affirmative, and normally they’d be fighting tooth and nail about getting treated like backup, but it seemed like even Dean knew that it wasn’t exactly smart to run in a weird-ass world with _no genders_ blind because he just quips, “Yeah, we do. Fucking jackass, but I gotta admit, hiding in a beta? Smart.”

Sam clicks his tongue in agreement, and Other-Them just shake their heads. “Look, whatever. This, this ‘mating glands’ or ‘scenting bands’ or whatever aren’t going to, like, mess anything up, right?” Other-Dean nods in approval when Sam and Dean both say the affirmative, and then he goes to leave, before freezing, staring at Dean’s neck.

“You have a human bite mark on your neck, dude,” Other-Dean says carefully, but his voice is taught, matching Dean’s wide eyes and tense body. “We can… do you want us to get Cas to heal it before we go?”

Sam’s eyes widen and he immediately shakes his head, even as Dean growls, “You will do _nothing_ to it.”

 _Cas is alive? Cas is alive. Cas is_ alive. Dean’s back, for a millisecond, relaxes, and then tenses up again because — _Their Cas is alive._ Their _Cas._

Other-Them freeze, wide-eyed. “We didn’t want to offend you!” Other-Him yelps, trying to do damage control, but knowing that Dean’s mate was _alive_ in this universe was just bad enough. “Look, I— we have some books on human anatomy and genders if you guys want to… go through it, or something. We… we should be back in a day or something, if we aren’t… emergency numbers are programmed into the Bunker.”

Other-Him shakes his head, chuckling, and mutters, “Feels like I’m having someone babysitting the Bunker, what the hell.” Other-Dean snorts, knocking shoulders with him as he picks up the empty case of beer. It was weird, seeing them take social cues from body language alone. Dean’s scent was strong enough that Sam could almost feel the anguish like it was his own, a faint imprint of Jess’s blood falling onto his mating gland in a cruel mockery of what could’ve been, and yet Other-Them didn’t _notice_.

When they finally leave Sam glances at Dean out of the corner of his eye, and the both of them just sigh, leaving the elephant alone in the room in the way Winchesters were all-too-skilled in doing. 

“I’m going to check out the books that… other-you mentioned, try to figure out what hellhole we landed in.” Dean gets up, shaking his head. “God that’s weird to say,” he murmurs, and Sam just looks at him out of the corner of his eye, trying to gauge what he should do. When Jess and Eileen had died Dean had been there for him, and now he wants to help Dean back. Still, Dean’s acting like nothing’s wrong, even going as far as seeming to consciously try to stifle his scent.

“Dean…”

“What?”

“I— It’s okay to be sad, you know that, right? Hell, I was… I mean, I still _am_ a mess from Jess and— and Eileen, and I wasn’t even mated! I wouldn’t be surprised if you— all I’m saying is if you want… if you want to talk, or— or to rest, you _can_ do that. We’re kinda going through a lot, Dean. Our world’s _literally_ been turned upside down.”

“Wouldn’t be the first time, Sammy.” Dean rolls his eyes, fists clenching and jaw tightening. “Look, I’ve already gone through C— through Cas dying, okay? I know how this works. And right now I just need to take my mind off things, relax.”

“I’m just saying—”

“I’m good, Sam. Really.”

“De—”

“ _Sam_.” He stays silent and watches Dean close his eyes, taking in a breath. “You know what, fine, knock yourself out. Check out the library. I’m going to be in the kitchen.” _I’m going to be drinking myself to sleep on the table._

Without waiting for a response Dean leaves, and Sam closes his eyes, letting his head rest against the top of his beer bottle. The important thing was that both of them were still alive. They could deal with Dean later.

* * *

“We’re back!”

Sam looks up from the books he’d been pouring through, the clang of the bunker door closing punctuating the words. Back in their world (and wasn’t that a sentence he never thought he’d say?) they’d only used the bunker for a year or two before giving it over to Claire and Krissy when they moved out, but navigating the old controls again gave him nostalgia that he didn’t even have when he saw the Other-Them get in Baby.

Other-Dean walks down the steps, tossing the keys in the air before shoving them in his pocket. It’s almost as easy to read Other-Dean as it is to read _his_ Dean, something that once would’ve terrified Sam but now just registers at number 7 on the list of things to deal with (eyes flicking side to side, _something happened,_ left arm too still, _something with Cas_ , footsteps sinking in the floor, _something he feels guilty for_ ).

“Where’s… _Sam_ ,” he says, and it almost brings him back to the days of Meg and Lucifer and even Gadreel, referring to himself in the third person like that. Other-Dean shoots him a look at his choice of vocabulary but doesn’t comment, thankfully.

“He and Cas took his weird-ass pimp car, they’re getting Jack… _McDonalds_ or something.” The disgust for the food chain in Other-Dean’s voice is evident, and Sam just snorts, deciding not to ask who ‘Jack’ was. There were more important things at hand.

“So… Cas. Does he— does he live here? With you guys?”

Other-Dean raises his eyebrows and Sam’s torn between being happy that Dean’s sleeping so he doesn’t have to hear the conversation and wishing Dean would wake up so Sam wouldn’t feel the absence of Other-Dean’s scent enveloping him, so he wouldn’t feel like Other-Dean was almost… _dead_. 

“Yeah… didn’t, for a while there, but I think he’s sticking around this time…” Other-Dean trails off, lost in thought, before shaking his head. “Anyway, Sam ‘n’ them’ll arrive in a few minutes, and then we can talk about…” he waves his arm vaguely in the air, “…this.”

Sam nods, but the pit in his stomach only grows. He wasn’t sure how much Cas in this universe would affect Dean, but the best possible scenario would be nothing happening, which would almost be worse than Cas being dead in this world. “I’ll go wake up Dean.”

Chewing on his lip, Other-Dean grunts in affirmation, seeming not to notice the almost identical expression on Sam’s face. Sam gets up and puts the books away, closing up the page with the highly detailed anatomy of a human’s nose. He’s about to leave the room when he stops and looks at Other-Dean. “I know this is going to sound weird, but… what is Cas to— to you guys?”

Other-Dean blinks up, and his eyebrows furrow even as he answers. “We’re… friends. He’s practically a brother at this point, really.” 

The abject disappointment in his voice is enough for Sam to get the picture so he just thanks him and leaves and tries not to think of what a train wreck the day was going to be.

He walks down the hallways, ignoring the way his footsteps echo, almost making him feel like there was someone walking down the hallway with him. Even the last couple of months, when they’d started taking cases again to figure out what the hell was going on with the world, Sam had never felt this out of it. It was easy for his mind to play tricks on him, for him to hear distant bangs and practically smell sulphur permeating the air as the hallway lights flicker. 

Just as soon as it came it disappeared, the lights returning to their golden glow, and Sam still pauses, shaking his head and then walking to what he and Dean had figured was a guest bedroom. He almost knocks on the door before he realizes it was already open a smidge and walks inside, seeing Dean sit on the bed, staring at the wall.

“This is Cas’s bedroom.”

 _Oh_. Fun. Dean’s hands are tense, curled up into balls and shaking. From the red in his eyes it was obvious that when he entered the room 12 hours ago with the intention of taking a nap it had never actually happened, but Sam knew from personal experience that now sleep wouldn’t come until two weeks later, so he says nothing. The silence hangs for a moment, tall and looming, before they hear the bunker door open again and footsteps patter down the steps in the distance.

“The, uh, the ‘us’ are back now. The ‘ _other-you_ ’ wanted us to go to the War Room so we could… talk.” Sam hesitates before continuing, “Their Cas is going to be there too.”

Dean looks at him, unclenching his hand that seemed to have been in that position for hours. Without saying a word he gets up, eyes lingering on Sam before shaking his head, patting him on the shoulder. “C’mon.”

They gather in the War Room, and Other-Dean tosses Dean a beer, unscrewing the cap to Sam’s and sliding it across the table in what almost seemed to be an instinctual movement. Dean’s eyes linger on the naked neck of the bottle but says nothing, and Sam just picks it up after a moment, raising it in a quick thanks. 

The silence is awkward, broken only by the distantly-approaching footsteps of whoever else was coming. 

Other-Dean finally clears his throat, leaning forward. “I’m guessing you guys know who Cas is? Jack’s… resting, and I figure from Sam you guys do have _a_ Cas, but… I don’t know what you guys have in your… _world_.” The tone of Other-Dean’s voice has Sam thinking he was going to use another word instead, and he almost doesn’t want to know what it was going to be.

“Yeah, we uh— we have— _had_ a Cas in our world too. Don’t know how you guys trusted him, though. The only reason _we_ did was because of—” Dean’s voice cuts off while Other-Dean’s eyes narrow, flicking down and back to where Dean’s arm tenses, flexing and unflexing in his lap. “Well. Anyway. Don’t know how you’d trust a demon, but something must’ve changed.”

Other-Dean raises an eyebrow, but before he can answer the footsteps sound loudly as Other-Him and Other-Cas round the door and Sam lets out an involuntary growl even as Dean’s eyes widen and then settle. Other-Cas has a scent — _has a scent_ — but it’s weird, _wrong._ The sulfur trademarked of demons is missing, and instead he smells like lightning, the ozone that Hannah — and, later, Anna — had. Worst of all?

He smells _unmated_.

The whiff of Dean’s scent that Cas always had after they’d officially mated was missing, replaced with thunder and lightning and something very, very _wrong_.

Next to him, Dean flinches, his hands flexing in his lap even as he stares, open-mouthed, at Other-Cas. It’s obvious that Other-Them notice, even if Other-Cas doesn’t, but for a moment it’s just too much, the changes between worlds, and Sam just wants to curl up in a ball and sleep and wake up with a suitcase packed for his and Eileen’s next road trip and Dean and Cas a block away.

“…Guys?”

Sam and Dean both blink, and even as Dean’s scent begins getting filled with something almost like betrayal, they both slip their game face on. Dean opens his mouth to answer and Sam realizes that he had never _told_ Dean about his and Other-Dean’s conversation and so he nudges Dean, flicking his eyes between Other-Dean and Other-Cas in code they’d perfected when they were practically two.

Dean pauses, glancing, and then he just nods. “Sorry, it’s… the Cas that we— that _we_ know is dead, so it’s a little…” he waves his arm in the air in a semblance of levity that doesn’t really hit. “…unsettling.”

Other-Them still frown but say nothing, and so Dean says nothing. Other-Cas frowns, though, and Sam can’t help but sneak another glance because the Cas _he_ knew would laugh and make a dumbass comment and smoke a joint, not just stare in silence.

“So…” Other-Dean breaks the silence, and the awkward moment isn’t forgotten as much as shuffled to the back of their heads as they all subconsciously lean forward, the universal ‘let’s figure this out’ stance. “What are we going to do with you— us?”

“We could stay here? Help out? I mean, we might not have been hunting for a while, but if this is as big as it looks like… I mean, we’re the _Winchesters_ , man.”

Other-Them look at them curiously even as Sam shoots Dean a worried look — if Other-Sam was as attuned to to his brother as Sam was, then Other-Them should’ve noticed the way Dean was sweating, how he was clenching and unclenching his right hand under the table, the only sign of pain that he would allow himself. Although Sam understood what Dean was saying, this time there were two of them — instead of normally pushing through like they normally would, maybe they could rest and let the _Other-Them_ take care of it. And if Other-Them had half the brain cells Dean and Sam already did, they would realize that too.

So he watches raptly Other-Them look at each other, trading glances before looking at Other-Cas. “Not sure if Billie would even let us, with her ‘rules’,” Other-Him finally mutters, and Other-Dean’s face pinches uncomfortably. 

“…Billie. Fucking hell. Sam’s right. You guys are retired, right? I guess we’ll… call on you if we need help?”

Sam’s eyebrows raise even as Dean shoots Other-Them a look. “ _Billie_? Who the hell’s that? I didn’t know we took orders from anyone.”

“Long story. She’ll probably want to see you guys anyway, been on our ass about ‘large displays of power’ and how ‘we’ll alert Chuck’.”

Other-Dean and Other-Sam roll their eyes, even as Other-Cas interrupts. “She _does_ have a point. And as much as I would… rather not, I think she’d also like to see you two, figure out how you did what you did.”

“Yeah, how _did_ you guys get through the portal? Back here, at least, it took us… ages to figure out the portal to another world, and almost a year to get the grace of the spell.”

Sam blinks, and he has to admit, he’s a little surprised that Other-Him’s backed off the mating thing so quickly, especially because he seemed so interested, but he guesses he knows himself and so he just answers the other question. “We used the grace extraction thing — don’t know if you guys have the same thing here, but back in our world, we found a needle in the Men of Letters’ bunker that took the leftover angel grace from an empty vessel, and used it on me to get Lucifer’s archangel grace, and then just got the other stuff.”

Other-Them stare at him, and just as Sam starts to wonder if there’s even _grace_ in the world, Other-Dean tosses back his bottle of beer. “We’re fucking _idiots_.”

They snort and then Dean shakes his head, almost throwing off the humor. “Won’t argue with you there. But who the fuck is Billie?”

“Death.”

Before Dean and Sam can even get started on _that_ particular change, Dean winces a little more obviously than he normally would, and all eyes shoot to him.

“Are you… alright?” 

Other-Cas was squinting, eyes focusing on Dean and probably making it worse as he gave all his attention to him. Sam himself could only imagine what was going on with Dean—your mate, in another world or not, smelling unmated? Rejecting your scent bond? That was tantamount to saying no at the altar and then throwing acid on the mate’s face, according to people back in their world. Dean was already beginning to look sick, and Sam could only think it would get worse the longer they stayed there.

“I— yeah. Look, Dean— _your_ Dean—’s right, Dean and I’ll go, find some small town to hole up in while you guys… work things out with— with ‘Billie’.” Even as Sam gets up he can tell that Other-Them won’t let go so quickly, especially with the little they knew about the change in ‘genders’, and so he just watches with a sinking stomach as Other-Them exchange glances and stand up too — fighting would be idiotic at this point, so it’s practically already a loosing battle.

“No, I’m pretty sure Billie would want you guys to stay here, figure out what you guys did — look, Cas can just heal you guys, and if not, I mean, the bunker’s the safest place to be, y’know?”

Still, Sam’s pretty sure Other-Dean’s saying that more out of suspicion than generosity, so he shakes his head and says no even as Dean winces again, and Sam barely has to catch a whiff of his scent to figure out that they need to get away from Other-Cas, _ASAP_.

Before he can say anything, though, Other-Cas steps forward and presses his hand to Dean’s forehead, his hand spritzing for a heartbeat before glowing, presumably to try to ‘heal’ Dean’s shakes. Dean physically jumps, and Sam’s eyes widen and even as he goes to break it apart Other-Him is already there, quickly pulling Other-Cas away from Dean. Other-Dean watches with narrowed eyes as Sam rushes up and tries to soothe Dean’s scent to no avail.

“Fuck, fuck, _fuck_ ,” Sam whispers, and it seems like Other-Cas trying to heal Dean must’ve sped something up in the reaction process because now it was looking like Dean was going through heat two months early, the one time they didn’t have any extra suppressants. He couldn’t even begin to understand how that worked, but now it was practically the worst thing possible.

Dean’s eyes go wide, and it’s obvious he’s figuring this out too, because his hands shake as he still pats himself down, going through his wallet and only finding empty Trojan wrappers. “Shit.”

Other-Them are staring, and Other-Cas is frowning, rubbing his hands together almost like he was trying to get the grace back in it for round two. “Look, Cas— Castiel, thanks for your help, that that’s… that’s really all we need, thanks.”

“What the _hell_ ,” Other-Him says, and it looks like both the other Winchesters had problems with volume because it seemed to have come out much louder than he had intended.

“Do we— if Cas didn’t help we have spells in the bunker, there’s _got_ to be something there that can help.”

“It’s— it’s good, it’s fine, don’t worry about it.” 

Personally, Sam finds it almost ironic that it’s Other-Dean telling Dean (telling himself?) to take better care of himself when he’s pretty sure he himself wouldn’t do it which brings up a pretty interesting psychological question that he doesn’t want to think about.

“Dean—” All eyes turn to Sam but he carefully takes in a breath and looks at him. “—we should probably go to the kitchen.”

Dean nods jerkily, his skin sweating even as he clenches his hand, walking practically a mile out of the way just so he was out of Other-Cas’s way and didn’t smell him as they went to the kitchen. Reaching there, Dean rests his hands on the cold metal, and Sam has to admit, his accidentally bringing Dean to the one comfort place that could calm him down was pretty smart.

They don’t say anything for a bit, and then Dean brings his hands up and cards them through his hair. “This is…” he shakes his head, snorting, “this is so stupid.”

“You don’t say,” Sam murmurs, and he can hear Other-Them and Other-Cas talking on the other side of the wall and he just wants to scream. They’ve only ‘lived’ for 24 hours and it’s already been more stressful than a month of their domestic life back in their world.

Back in their world.

Jesus Christ.

“Look, maybe I should just… tell Cas to get out, or something. Don’t think they’ll let us leave, not with ‘Billie’ or whatever.” It’s weird, saying ‘Cas’ but picturing someone entirely different from the lazy-ass demon that saved Dean from hell because he thought he was ‘pure’, and then proceeded to invite him to orgies on five separate occasions. This new Other-Cas seemed to require all three syllables of his name instead of the one that suited Dean’s mate perfectly.

“Stop being such a fucking knothead, it’ll be fine.” Dean groans, taking in a breath even as he forces himself to stand straight. “Hell, I was in purgatory for a year, right? Barely had suppressants for one day of heat, forget two weeks of it. But I figured it out. I can… I can do it again.”

It’s obvious from the tone of voice that that wasn’t fun, but Sam has to admit, Dean has a point. It’s not like they have extra suppressants to help them out. Still—

“Are you sure? I mean…”

“ _Sam_. Besides, after this, we’ll have an entire half year to figure out how to get actual suppressants made.” Dean shakes his head and then forces a smile. “Besides, look at the bright side — if Chuck actually does kill the world, it’s not like I’m going to need them anyway.”

“ _Fine_. We still need to tell Castiel, though. If he hangs around or tries to heal you again, I don’t—” Sam cuts himself off when he notices Dean raise an eyebrow at the ‘Castiel’, even as his hands shook, his face turning steadily red as it seemed like Dean was bodily stopping himself from throwing himself out the door and confronting Other-Cas like he was his.

“Dude, no,” he says, sounding almost distracted. “they gotta figure it out for themselves or I'm gonna freak out. Him. That me.”

“Dean, we can’t do that. I mean, looking at their— their Cas, I don’t think they’re just going to take ‘sorry, he can’t be there’ lying down.”

“Remember how I reacted when Bobby told me that our scent-bond is — _was_ — real? Can’t imagine it would’ve gotten better with time.”

Sam purses his lip at Dean’s slip-up and it hits him, again, that Cas is _dead_ , and Dean barely has any time to process it. He guesses that is, in itself, part of their grieving ritual at this point, but it can’t make it any easier.

“Can’t imagine your trust issues got better with time, either.” It’s a low blow, and Dean just glares and stares at Sam, shaking his head. Sam knows he shouldn’t be doing this — hell, in Dean’s current state, he should barely be able to construct a proper sentence, let alone make a sensible argument, but unhealthy is their middle name so he presses the point and Dean gives.

“Fine! Fine. Just…” his voice trails off and Sam nods, sobering up.

“Yeah.”

_Just don’t make me look at him._

* * *

They get out, and it seems that Other-Them’ve talked something out because they’re no longer in the War Room, instead sorting through the bookshelves and pulling out books seemingly at random.

Other-Them all look up when they see Dean and Sam leave the kitchen, and at this point Dean’s practically leaning on Sam as they walk up the steps, obvious in their attempts to be subtle.

“We’re gonna stay here for a bit… Dean’s going to have to have a room to himself, though, to be safe.” Next to him, now leaning on a pillar, Dean snorts, but Sam continues when he doesn’t make an effort to clarify or interrupt. “And your world’s, uh, your world’s Cas — it would be better if he wasn’t really there either.”

Other-Them scowl, almost defensively walking closer to Other-Cas. “And why?” Other-Dean spits, accusatory, while Other-Sam just furrows his brows and seems to be trying to remember something.

“Remember how I said I was mated?” Dean says, straightening his back and taking his weight away from the beam for a moment even though it must’ve been hell as the attention’s brought to him. “Yeah, I was mated to Cas. Our world Cas.”

He says it nonchalantly but it’s obvious that it’s a loaded mine because no one says anything, almost holding their breath as a group and waiting for Other-Dean-and-Cas’s reactions. They don’t say anything, and then Other-Dean pauses, staring at Dean. “I’m not gay.”

“He’s an Alpha, I’m an Omega — that’s about as heteronormative as it gets. Believe me, I’m not gay either.” Dean snorts, but he’s staring down Other-Dean now, and Sam can’t help but notice how Other-Cas doesn’t say anything, just looking at Other-Dean with something almost like curiosity in his eyes.

“In this world, I’d say it’s pretty gay,” Other-Dean retorts, and Other-Cas looks at Other-Dean, eyes dropping as he marginally moves away from Other-Dean. Sam can’t help but wince because Other-Dean’s reacting practically exactly like Dean had predicted and so he just shakes his head.

“Look, you guys can do this later, okay? Right now, Dean needs to settle down, we can figure this out later.” Sam uses a little bit of his ‘teacher-voice’ and suppresses a snort at the way Other-Them seem so surprised by it. He waits, a beat, and when no one argues, he nudges his head and then Dean walks over, both of them leaving quickly.

They pointedly walk past Other-Cas’s bedroom and find some other, empty one, and Sam decides not to mention the whiff of sulfur in the air as they pass by the bedroom — it would be too much, after their whirlwind of the last 48 hours. Dean practically collapses in the bed, rubbing his crotch against the sheets and closing his eyes. Sam hopes Dean either doesn’t realize or forgets Sam’s still there because no matter how close they are this isn’t exactly something he wants to see, and so he chews his lip and leaves, heading to the kitchen.

On his way there, he passes the library again, and this time he’s struck by the change in mood — Other-Dean and Other-Cas, while before easily stepping in the others’ ‘personal space’, are as far away from each other as possible, with Other-Dean seeming to have been staring at the same page in the textbook for the past ten minutes and Other-Cas sneaking glances at him. All in all, the tension in the air could be cut with a knife, and while Sam would normally get up in their business about it this isn’t his world so he just shoots them a look and glances at Other-Him, who’s staring at Other-Dean-and-Cas with narrowed eyes.

In the kitchen, he pauses before rifling through the cabinets, finding the honey and eventually putting a pot of water to boil on the stove. As much as Dean hated the stuff, he’d once confided in Sam that it was pretty good when he was stuck without Cas on heats, and so Sam taught himself to brew tea, just in case.

Looks like it was finally going to be used after all.

He’s looking for the lemon when he hears footsteps and he lifts his head up, meeting the eyes of Other-Him. He’s leaning against the doorframe, hands awkwardly shoved in his pockets as his eyes roam over the kitchen, glancing at the stove and keeping his gaze there. Sam pauses, waiting, but when Other-Him doesn’t look like he’s going to be saying anything anytime soon, he continues his search.

Finally, Other-Him says, “If you’re looking for the lemon, it’s in the fridge.” Sam looks up and Other-Him purses his lips, gesturing vaguely to the stove. “Honey lemon tea, right? I used to— used to make it for Dean, when he was sick. He didn’t know it, but…” Other-Him shrugs, chuckling awkwardly.

Sam blinks at him and then puts a half-smile on his face, not sure how to respond to that. He isn’t quite sure what it means to be ‘sick’ but he’s guessing it’s similar to being in heat (or, God forbid, rut), so he shrugs and finds the lemons and begins grating them. A few moments later Other-Him awkwardly clears his throat and walks forward, reaching out to, presumably, help grating the lemons.

It’s weird, seeing him like this, and Sam kind of finally understands what people mean when they say Sam might look like an Alpha but doesn’t act like one. Hell, if Sam didn’t remember his presentation, then he would think Other-Him was a beta, despite all the gangly limbs and shaggy hair.

They work together in silence, and then Sam decides to take the first step forward, this time. “How’re— how’re Dean and Cas reacting to this?”

Other-Him shakes his head, snorting as he squeezes the lemons. “Idiots as always. Back when Charlie—” Other-Him coughs, something flitting across his face before he continues. “Back when Charlie was still… around, we used to have a betting pool about when they would finally get back together. Five years later and— I think even _they_ can’t miss this.”

It’s obvious that Charlie is a sore subject and so Sam doesn’t bring her up, ignoring the way his own heart pangs at the fact that their own Charlie had chosen to stay behind in that world, spending her final moments with Kara by her side.

“We talked to Cas, about the, uh, the ‘mating’ thing you guys brought up, and…” Other-Him stops squeezing the lemons and instead leans against the countertop with Sam, talking as they wait for the tea to steep. “Well, Cas’s— according to Cas, the only similarities he can find between your guys's… ‘genders’ and our world is that angels mate with bite marks, too, and so the working— the working theory is that in your world, Chuck decided it worked well on angels and so he gave it to the monkeys, and then the monkeys evolved, and in this world, it didn’t end up happening.”

Sam nods, almost to himself. “Makes sense.” He waits, for a moment, for the question he knew he would eventually ask, and he isn’t disappointed.

“What’s… what’s up with Dean?”

He waits for a moment, because from the little he could see it seemed like sex was pretty taboo in this world (which was weird as hell), but… well, it would be awkward as hell if someone walked in Dean’s room meaning well.

“He’s in heat,” Sam says carefully, and he notices the way Other-Him’s eyes spark with curiosity, even as Other-Him seems to notice Sam’s cautious body language. He takes the tea off the stove, busying his hands as he continues the conversation he never thought he’d have to give. “It’s— we mentioned Dean was an Omega, right? They have… there’s an ‘innate instinct’, I guess, to reproduce with their— with their mates, twice a year. As society’s evolved, obviously, people don’t have kids that often, but it’s still stayed. Cas— he normally helps Dean through them, but…” Sam scoffs, shaking his head, and lets Other-Him finish the train of thought.

“What about— would our—'' Other-Him clears his throat before continuing, speaking the rest of the sentence in one breath. “I mean, we’d obviously have to check it with him, but— would our Cas — our world Cas, sorry — work to— to help?”

Sam’s eyes widen and he pauses as he grabs the strainer, eyes flicking as he tries to formulate the answer. “I mean— he could but… from the way Dean’s body, uh, reacted to ‘your world’ Cas, I think— I’m pretty sure the only way it would work was if he was _mated_ to Dean, which, if it was anything like in our world, is a— a pretty big deal. I’d think your, uh, Cas would want to— want to save it.”

Other-Him says nothing, for a while, and Sam fills up the cup of tea and then grabs some random junk food he thinks Dean would need, before heading over to the door. For a moment, he thinks that’s the end of their conversation, but then Other-Him says, carefully, “I— okay. Dean’s— he’s okay, though, right? Safe?”

It’s Sam’s turn to hesitate.

“I hope so.”

* * *

The room Dean was staying in, tucked away in a corner of the bunker, two storage rooms sandwiching it, was dusty and musty and perfect. While it may not have been the best — Sam quickly figured out that there weren’t even knots, let alone Alpha pads, anywhere near the bunker — it would (hopefully) be private enough for Dean, and the bathroom’s weren’t too far away. Still, going through heat without your mate when you _had_ a mate, according to Charlie, was one of the most difficult things she’d ever done.

When your mate was _right_ there?

Sam was pretty sure that was tantamount to torture.

On his way there he finds Other-Cas, apparently having slunk away from the library at some point during Sam’s conversation with himself, apparently coming from the dead end hallway that Dean’s room’s in. He’s tempted to stop and see what the hell happened, or break into a sprint and rush to find Dean, but Other-Cas gives him one look and nods soberly and Sam shakes his head. There’s no reason to get worked up.

Duh.

But he still makes sure there’s no one there (again) because though he’d occasionally heard Dean going through heat whenever he couldn’t get to Bobby’s fast enough in their teen years, Dean’s still his brother and he likes to think he respects his privacy, so he can feel the blood rushing to his face (and holy shit he’s glad that scents include familial bonds otherwise this would be awkward for everyone involved) when he reaches the door. The scent, which had only just been growing when he walked Dean to his room was now practically a wall of _want want want_.

There’s a distinct fruity tinge to it that only happens in heat — Sam’s pretty sure it’s watermelon with some kiwi— but even with that, there’s something strange, an aura of lightning crackling that makes no sense. Sam hopes that it’s just Dean’s body’s reaction to Other-Cas because if not, if it wants Other-Cas from their meeting or something, not _Dean’s_ Cas — what with Other-Dean and the rest of the fucking gender-less world, it was going to be a goddamned nightmare.

He hesitates and then opens the door, finding Dean naked on the bed, his hand covered in his own slick and clutching his cock while his eyes, half-lidded, are raised towards the ceiling with a constant litany of “Cas, Cas, _Cas_ ,” the only sound in the room other than his pants and the crinkle of the bedsheets.

Sam winces and drops the food off, Dean seeming to finally register Sam’s presence when he pops back from one of the neighboring storage rooms and grabs a change of bedsheets and a towel that Dean would, hopefully, thank him for later. 

Either that or Dean would use gouge Sam’s eyes out with bleach, but he likes to think it’s the former.

When he, finally, leaves the room, he can already feel plans writhing under his skin, he can already think of ten different ways to try and solve the whole ‘mated but not mated’ thing that don’t include death, and seven for the ‘heat and ruts without suppressants’ — unfortunately, all of the latter include some form of alcohol, which couldn’t be sustainable. But still, Sam’s busy. So it’s understandable that he loses track of where he’s going and bumps into her.

He thinks he took a wrong turn somewhere past the shooting range because now he’s next to the infirmary when he meant to go to the library and read up on angel anatomy, and suddenly there’s a very dangerous-looking woman standing in front of him and holding a scythe.

He thinks he vaguely recognizes the weapon from the days of Apocalypse numero uno, back when the Horsemen were still in the playing field, which means…

“You’re Billie,” he hedges, and judging by the appraising look she gives him, he’s right — then again, if he was wrong, that would mean the woman was an intruder and therefore he would’ve been dead before he could even have seen the scythe, but you win some, you lose some. 

“And you’re Sam Winchester,” she says, and her voice — low, careful — already puts him on edge. He shifts his stance, slightly, and ignores the whiff of sulfur in the air again — at this point, he’s wondering if he’s smelling his own scent, which would be both annoying and a useless side effect of the world he didn’t need.

She looks him up and down, her eyes pausing on the virgin mating gland on his neck, before continuing just as Sam was about to try and leave. “Y’know, that little trick you and your brother pulled almost broke the wards here in the bunker — I was tempted to just get rid of you there and then before you guys called Chuck and rained hellfire down on us all.”

Sam narrows his eyes and resigns himself to the conversation. “Why didn’t you?”

Billie shrugs — slow, languid — and with it the scythe disappears. “Four Winchesters are better than two, it would seem,” she says, and then, almost conspiratorially, adds, “besides, Winchester souls are special. It would be… _horrible_ if they were lost.”

He snorts. “You, according to us, have some plan? I don’t think you saved us just out of the goodness of your heart.”

She looks at him again, before continuing. “You take the Winchester out of the hunter but you can’t take the hunter out of the Winchester. Y’know, you and Dean — you guys were Chuck’s favorites until you went off-script and decided to settle down, ‘grow a family’. But he was so _personally_ invested in you that your souls? They’re special. And I would hate for you to have died and powered up Chuck. Again.”

The resignation in her tone, the way she looks at him — smirking, taunting — makes Sam wonder how many Winchesters she’s seen, how many’ve ‘been Chuck’s favorite’. How many went off-book. How few stayed.

“That’s not all you’re here for, is it,” Sam hears himself say, and even as he speaks the words the puzzle pieces fit together in his head. “You’re— you’re not here to check up on us, or the regular Winchesters. You could’ve done that from anywhere. You’re here for something else, aren’t you?”

Billie smiles, for the first time looking like she means it. “Smart boy, Sam. Y’know, in another world, you could’ve become a Harvard Law Professor instead of just teaching kindergarteners their ABC’s.” She smirks. “Oh wait. You did. Then that you died in a car accident the same day Dean died in the line of duty. The next day, that world crumbled to pieces. Funny how these things work out, isn’t it?”

“Answer the question.”

There’s shuffling in the background, the sound of a few sobs, and it hits Sam that there’s someone in the infirmary. Currently. Listening to their whole conversation. Billie follows his eyes and chuckles — low, amused — but doesn’t say anything on that.

“You’re right, Sam, I do have a plan,” she says after a beat. “Here it is. You and Dean and Castiel? Your world Castiel, sorry.” She adds, and something twinkles in her eye when Sam’s heartbeat speeds up, when something all too close to _hope_ burrows in his chest. “Go to California, settle down, live your life. You don’t get involved in hunts at all. In fact, you barely leave your house. You guys have the easy job, Sam. You guys? You just need to _live_.”

“Wh- What?” He hates how his voice wavers, how all that’s running through his head is _yourworldcastielsorryyourworldcastielsorryyourworldcastielsorryyourworld_ on a loop.

“I wasn’t lying when I said your souls were important. Every Dean and Sam Winchester, at one point, was Chuck’s favorite. But he’s made so many of them that he’s forgotten how to make worlds, Sam. In fact, he’s started making worlds that revolve around you and your brother. He isn’t destroying worlds. He’s killing the you two that live in it, and waits for the rest of the dominos to fall.”

The scythe reappears in Billie’s hand, and she looks at Sam expectantly, waiting for him to make the connection.

He pauses and asks the question he doesn’t care about. “You mean our world— our world still exists?”

Her tiny smirk is all the answer he needs when she continues. “Of course, I can’t bring you two back there, because Chuck would notice, but one tiny, insignificant, alternate reality still running? Barely a blip on our radar. But recently it’s come to my attention that one stoner demon is trying to break the wall between worlds, which _would_ cause Chuck to take notice, don't cha think?”

The little hope begins to shrivel up and die and Sam says; “Either you bring— you bring our world Castiel here, safe and healthy, or me and Dean? You’re going to be reaping two new souls very, very soon.”

Of course, he doesn’t mean it, but he still stands his ground when Billie stares at him and then laughs — cold, shrill — and says, “My, my, look at you, standing your ground. Don’t worry, a suicide pact isn’t necessary. Just think of this as… my gift to you.” She winks, and then just before she raises her scythe, she says, “Oh, and by the way, make sure to tell Sam — the other Sam — what I’m doing. I think he’d like to know.”

She slashes her scythe through the air.

**Author's Note:**

> tw for casual transphobia — our world dean mentions that being male = having dicks obv not true its a throwaway line early on figured u should know:) and brief mention of a suicide pact — alternate sam threatens to have him & dean kill themself if Billie doesn’t agree to terms of a deal 
> 
> Ahhh yes i know the ending is way too rushed + the tonal shift is WILD but i wrote the beginning a month ago, the middle during varying times, and like the rest of it today so...
> 
> I know i should’ve gone beyond that but i didn’t have the energy and lk i liked where it was at so i ended it there (but if u wanna know after that she brought Cas back, tearful reunion, Cas helps dean, etc.)
> 
> (Not gonna lie I’m not a huge fan of this, but i started writing it and i felt like I HAD to finish it, so.. hopefully its passable)
> 
> (Also yes the insp for demon!cas was endverse!cas don’t @ me)
> 
> Don’t be shy to drop a comment + kudos (and yes i accept constructive criticism lol)


End file.
